docs: def get_page_number_from_request(
          request, querystring_key=PAGE_LABEL, default=1):
      """Retrieve the current page number from *GET* or *POST* data.
      If the page does not exists in *request*, or is not a number,
      then *default* number is returned.
      """
      try:
          return int(request.GET[querystring_key])
      except (KeyError, TypeError, ValueError):
          return default